Our long range goals are to identify, isolate and define at the molecular level the regulation of developmental genes in the model system Bacillus subtilis. For this proposal we intend to isolate and characterize a unique set of late sporulation genes in Bacillus subtilis involved in spore germination (ger). These mutants were recognized by their altered response to germinants and are normal in vegetative growth. Thus, this class of genes is sporulation specific but, unlike sporulation (spo) genes, produce viable heat resistant spores with a partially defective phenotype. They represent a class of genes expressed late in the sporulation process, potentially having unique mechanisms for control of expression. One group of ger genes are of particular interest for they also perturb the process of sporulation. With the recent discovery of a transposon which will function in B. subtilis and its development to enable the study of gene expression, the isolation of spo and ger genes is now relatively simple. Using these techniques we have been able to isolate colonies containing the gerJ genes and are in a position to isolate other ger genes. The objectives of this proposal are: (1) Characterization of the physiological and temporal expression of the ger genes; (2) isolation of more mutants producing heat sensitive spores; (3) genetic and physiological analysis of new ger genes, including promoter regions; (4) a study of penicillin binding proteins of gerJ mutants during sporulation; and (5) physiological and biochemical studies on late stage sporulation (germination) mutants.